There is a growing trend in laparoscopic surgery to be as minimally invasive as possible. This has pushed surgeons to perform procedures with fewer and smaller incisions. With more recent protocols, only one incision is made (in the umbilicus) through which all of the instrumentation and even the camera are inserted. While highly promising, this technique presents many obstacles including lack of triangulation, instrument reach, handle clashing, etc.
Various articulating laparoscopic surgical instruments have been developed in an attempt to address one or more of the above concerns. In general terms, an articulating laparoscopic surgical instrument includes an elongated shaft carrying an end effector (or “working end”) at the shaft's distal end. The end effector can assume various forms, such as scissors, graspers, needle holders, dissectors, clamps, electrocautery implements, electrode probes, etc. A wrist portion of the instrument (typically proximate the end effector) can be caused to deflect or bend. A handle at the proximal end of the shaft affords user control over the end effector and the articulating wrist. When employed with laparoscopic procedures, articulating instruments allow the surgeon to regain triangulation during single port surgery by aiming the shaft of the surgical instrument slightly away and then curving the working end (or end effector) back toward the operative site. In addition, their longer lengths provide the surgeon the reach needed for organs further away from the umbilicus. Further, their low profile handles minimize handle clashing at the entrance site.
To be truly viable, the articulating laparoscopic instrument should afford user control, via actuators along the instrument's handle, over operation of the end effector, rotation of the end effector, and articulation of the wrist or shaft. The mechanisms necessary to provide these multiple control features at the small scales associated with laparoscopic instrumentation are inherently intricate and dramatically increase the instrument's cost. In this regard, surgeons desire the ability to control, via actuators carried on or near the handle, all three movements (i.e., end effector operation, end effector rotation, and shaft articulation) independent of one another. An additional control feature provided with some laparoscopic instruments is an ability to rotate the outer shaft (thus re-orienting a spatial of location of any bend formed along the wrist or shaft). These requirements give rise to much technical difficulty, especially when accounting for the independent transmission of torque (for end effector rotation) from the handle actuator and through or around a bend in the wrist or shaft. While existing articulating laparoscopic surgical instruments may provide one or more of these features, they are limited to one-time use or are otherwise disposable because their design does not allow for proper cleaning and sterilization. Nor are they robust enough to stand up to repeated use. Due to the high cost, single-use nature of existing articulating laparoscopic instruments, a caregiver may unfortunately decide against purchasing or using such instruments. As a result, the single incision laparoscopic surgical procedures performed by the caregiver will be more complicated or even avoided.
In light of the above, a need exists for improved articulating laparoscopic instruments having a wrist joint assembly that facilitates desired surgeon control over instrument operation, articulation, and rotation.